Boring-machine.



G. H. SMITH.

BORING MACHINE.

ArPLwATIoN FILED 00T. 21, 1909.

959,083. Patented May 24,1910.

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UNITED STATES IAIEN T OFFICE.

GEORGE H. SMITH, OF PROVIDENCE, RHODE ISLAND. ASSIGNOR TO BEAMAN &.SMITH COMPANY, OF PROVIDENCE. RHODE ISLAND, A CORPORATION OF RHODEISLAND.

BORING-MACHINE.

To all wliom it 'may concern.:

Be it known that I. Giioiic-E H. SMITH, a citizen of the United States,residing at Providence, in the county of Providence and State of RhodeIsland. liave invented ce1'- taiii new and useful Improvements inBoring-Machines, of which the following is a specification.

T his invention relates to boring-machines and consists in the novelmanner of mounting, supporting and driving the ciittei'cai rying oiboring-spindle, all as more fully hereinafter set forth and claimed.

In machines or tools of the general class referred to, and as usuallydevised. cach is provided with a revolubly-driven central boring-barsupported at both ends, its rear end being centered in the tail-stoel;spindle.

In machines more especially adapted for blind or snout "`boring, wherebythe object to be bored has one of its ends or head closed, or possiblyhaving a comparatively small central liole through it, .inadequate forthe passage of a boringiai', as for example, in the case of certaintrunk-engine cylindeis, the boring cutters are mounted in the outer orfree end of the bar, the latter then constituting a revoliible beamhaving a support at one end only. In some cases, howeverz the cutter-baris extended, its rear end portion being revoliibly supported in abearing longitudinally adjustable on the bed of the machine.

There are objections to suoli former methods and practice, for example,it is almost impossible to fasten the bar in a revoluble head or chuckso as to prevent appreciable lateral deflection at its outer unsupportedend, this defect beingr cspeciallynoticeable in case a comparativelyheavy cut or chip is being made; and the hole thus bored will not betruc or uniform throughout its length. In order to insure greateraccurac in boring holes in such articles, a relative y lighter ornerfeed and chip are used, thereby necessitating a correspondingly greaternumber of cuts in removing the stock from the inner surface of the wallbeing acted upon so as to produce a bore of the desired diameter.Obviously, too, such boring operation materially increases the length oftime consumed and also adds to the cost of attendance. It may be addedthat the work being bored is securely fastened t-o a carriage or platenslidahly mounted on the bed of the machine and having its move-Specification of Le' `:ra Patent.

Application filed October 21, 1909.

Patented May 24, 1910.

Serial No. 523,905.

ments controlled by a feed-screw in a wellknown manner.

Iii case the machine has a comparatively long, revoliilile bar whoserear end is mounted in a bearing, as before stated, siifiicient freedomor play niiist be provided between the adjacent surfaces of the bar andits bearing to allow for and maintain proper lubrication. As thusdevised, more or less lateral vibration is liable to occur at that endof the ba r during its cutting or abrading operation, diie toinequalities in the stock or metal, variations in the cut or feed, &c.;iii fact, the bai' is subjected to varying degrees of torsion by reasonof such iiiieveiincss in the stock, thus producing irregularities in theboring of the hole. since the cutters then work in an intermittentmanner, or chattei' as it is termed.

The object I have. in vie-w is to overcome the above named disadvantagesin a simple and eilicient manner by providing boringmachines withimproved means whereby the cutter-carrying spindle is constructed torotate without lateral vibration or deflection, since its axis ismaintained in trae and rigid alinement. As thus devised, the machine iscapable of producing a n'iateiially increased amount of work and at aconsiderably reduced cost. Moreover, the holes thus bored are true andaccurate to size or gage throughout their length.

In the accompanying sheet of drawings, Figure 1 represents a sideelevation a boring-machine embodying,f in v present improvements, viewedfrom the front. Fig. 2 is a longitudinal sectional view, in enlargedscale, taken through the center of the 1mpioied boring-spindle, &c. Fig.3 is a top plan view of the cutter-head, detached, corresponding withFig. EZ. Fig. 4 is a partial longitudinal central sectional view taltenthrough the front or driving-head, showing a slight modification inconstruction. Fig. 5 is a similar view, showing the construction of theouter or rear end portionof the bar and spindle mcinbcis shown in Fig.4, being in fact a continuation of the latter, and Fig. 6 is a sideelevation in partial section and in reduced scale, showing a furthermodification of the invention as adapted to boringmacliines.

In order to'illiistrate the. adaptability of my invention. I haverepresented in Fig. 1 a horizontal boriiig-niac iine of well-known type,wherein lu. indicates the bed, C the driving-head. and F a work-holdingtable or platen, slidably supported on the bed, and adapted to beactuated by a feedscrew, snbstantiallvas common.

In lieu of the usual revolubly driven boring-bar mounted in the head ordriving end ofthe machine. I employ a central har member B, rigidlysecured in the head portion C, the bai` extending rearwardly from thelatter a suitable distance, the rear end portion being unsupported,substantially as represented in Figs. l and 2.

The revoluble boring-spindle proper, D consists essentially of a tubemounted and supported on said bar B. The front end portion of thespindle may be provided with an integral flange, d, (Fig. 2) and hub d1,

on which latter the driving-gear g is fitted and 1s secured to thespindle by means of bolts g1 passing transversely through 1t and I saidflange.

The cap member, which assists in securely clamping and holding the bar Bin position in the head or frame C, is provided with a radiallyextending flange c1, to which is vsecured by bolts or studs, f, anannular housing member, E, the latter having a narrow flange, c, at itsrear end, whose inner face is turned ofi'l true to serve as a bearing,in connection with the adjacent portion of the gear g, f or maintainingthe revoluble spindle 1n pos1t1on and preventing rearward movement. Acollar, a, may be interposed between the front end of the spindle andthe rear face of the head C to receive the force or working end thrustof the spindle. The spindle may he provided interiorly at each end witha fixed, lining or bushing, a1, of suitable anti-friction metal, andbored to lit the corresponding portions of the stationary center bar.

The rear or unsupported free end of the spindle extends a short distancebeyond the bar and is provided with a cap member, p (Fig. 2), removablysecured thereto by bolts m and key icl. A central shank, p1, extendsfrom the cap on which is fitted and keyed a collar or head H, havingsuitable cutters or tools, as lo, mounted therein. A screwthreaded stem,p2, projecting rearward from said shank part, in connection with a nut,n, serves to maintain the cutter-head in place longitudinally of thespindle.

The tubular boring-spindle D is or may be actuated by a pinion-gear g2meshing into the gear g. The power or driving force employed may betransmitted to the small gear g2 in any suitable or well-known manner.

In lieu of the construction shown in Fig. 2, the flange d may be omittedand the gear g keyed direct to the reduced end of the oring-spindle D1,as indicated in Fig. 4, and an anti-friction bearing, consisting oflaterally separated, flat, annular plates b and interposed balls b1,located between the face of the gears hub and the adjacent face of thehousingsl flange e. The other end portion of the spindle may be providedwith an inelosed thrust bearing, also formed of plates ZF and balls b1,disposed between the adjacent faces of the rigid bar B and cap s screwedto the end of the spindle. See Fig.

The drawing also represents the toolcarrying head Il as screwed to theshank s1 of the cap member.

In the modification shown in Fig. 6, the stationary center bar B iselongated and extends through the open rear end of the boring-spindle Dand is rigidly clamped or secured in a fixed support, w. In this casethe tool-carrying head H .is secured to the exterior of the spindle. Thedrawing also shows, sectionally, a piece of work, e. a hollow cylinder,2', fixed in a holder z, in' turn secured to the platen F. The revolublydriven boring-spindle carrying the tool-head is represented in the actof boring the cylinder while it is being advanced in .the arrowdirection. As thus arranged, the

rigidly held center har is not subjected to torsion, while vibration ordeflection of the bar is practically eliminated, thereby, through themedium of the driven boringspindle revolubly supported thereon, adaptingthe machine to produce more accurate, uniform and truer work and in amore expeditious manner.

It is obvious that machines thus equipped with the invention may bereadily employed for abrading or grinding away the metal and also forpolishing the inner surfaces of tubes, hollow cylinders, &e., by simplyproviding the head portion H of t-he'spindle with suitable other toolsand increasing the speed of rotation correspondingly.

The improved device forming the subject of this application for patentis well adapted to be employed in vertical boring-machines, in whichcase I prefer to. construct and arrange the boring-spindle D1, Sac.,substantially as represented in Figs. 4 and 5; obviously thelongitudinal axes of the bar and spindle members would then, however, bedisposed in a vertical plane. The upper or outer end ofthe driving-gear,g, secured to the corresponding end of the spindle, may be provided withan annular flange. c, having an intnrned lip, thereby forming an openreservoir for oil or suitable other lubricant; access to the reservoirbeing had through an opening, c2, formed in the extension c1; thelatter, through the medium of the flanged housing E secured thereto,serving to support the weight of the spindle D1 and the several partssecured to it.

I claim as my invention:

1. In a boring-machine, the combination of a stationary center-barrigidly supported at its head end only, a driven tubular boring-spindlerevolubly mounted thereon and extending outwardly beyond its support, a

adapted for holding cutting or abrading tools in its free end, and meansfor driving the said spindle.

2. In a machine of the character described, the combination with acenter bar rigidly secured in the head-stock or analogous member andextending rearwardly therefrom without other support, of a tubulardrivespindle revolubl; mounted on the bar, means for actuating thespindle, and means adapted for removably securing cutting tools to the sindle.

3. n a machine of the character described, the combination with acentral bar and holding means adapted for rigidly maintaining it in anormally Stationary position, of a tubular cutter-carrying spindlesupported by and revolubly mounted on said bar.

+L. In a machine ofthe character described, the combination of a centralbar member rigidly held against longitudinal and rotary movements, apower-driven, tubular, cuttercai'rying boring-spindle revolubly mountedand supported on said bar, and means adapted to prevent endwise movementof the thus mounted spindle.

5. In a machine of thecharacter described, the combination of a rigidlysupported cental bar member having a portion thereof cutter-carryingtubular spindle or sleeve revolubly mounted on said bars extension, andsuitably mounted anti-friction bearings arranged with relation t0 saidbar and Spindle members, adapted to prevent endwise movement of the s4indlel (5. In a mac xine ofthe character described the combination witha stationary central bar and a tubular Work-spindle revolubly mountedthereon, of a ca member secured to the outer or free end oi) saidSpindle and carried thereby, a cutter-head secured to said cap, and athrust-bearing interposed between the adjacent ends of said cap and barmembers.

7. In a machine ofthe character described, the combination with astationary, rigidly supported center bar and an annular boring spindlerevolubly mounted and supported thereon. of a revoluble driving-gearsecured to the front end of said spindle, and means adapted to receivethe Working end thrust of the spindle.

In testimony whereof, I have affixed my signature in presence of tivoWitnesses.

GEORGE H. SMITH.

IVitnesses:

CALVIN H. BROWN, GEO. H. REMINGTON.

